Bridge



Feb. ys. 1921.

c. Z'IMMERMAN BRIDGE A Filed Jan. 28,. 1926 w MN latented Feb. 3, 192.7.

vente Sire-frits mitad@ CASPER ZMMERMAN,.OF FORT COLLINS, COLORADO.

BRIDGE,

Application filed January 28, 1926. Serial No. 84,390.

f This invention relates to bridges and more particularly to the method of constructing wooden bridges. j i s An important object of the inventionis to produce a vwooden vbridge structure which is capable of being substantially completely protected from the elements by .sheathing with light sheet vmetal or similar material.

A further object of the invention is to provide a device of this character which may be readily and cheaply produced and installed, which will be durable and efficient in service and a general improvement in the art.

These and other objects I attain by the construction shown in the accompanying drawing, wherein foi-'the purpose of illustration is shown a preferred embodiment of my invention and wherein Figure 1 is a side elevation of a bridge truss constructed in accordance with my invention, the covering being remo-ved;

Figure 2 is a longitudinal sectional view therethrough Figure 3 is a section on the line 3-3 of Figure 2.

Referring now more particularly to the drawings, the numeral 10 generally designates truss members, each in the form of a compound truss consisting of a main truss 11 and a lesser or reinforcing truss 12 having a common base 13. The truss 11 includes the usual uppermember 14C connected with the base'member by inclined end members 15. The truss 12 includes an upper member 16 of considerably less length .than the upper member 14 of the main truss and abutting the under surface of the'member 14C at the center thereof. From the ends of this upper member, inclined end members 17 eX- tend downwardly to the base and these inclined end members preferably parallel the end members 15 of the main truss.

A pair of the trusses 10 are provided, these r trusses being connected by cross beams 18.

Of these cross members, the central cross member is connected with the upper ends of the end members 17 of theinner truss by turn-buckle rods 19 extending through the base member 13. The remaining cross beams are connected to the upper member 14 of the main truss by vertical rods 2() extending through the upper and base members of the main truss and provided with nuts whereby they may be adjusted to draw the beams dicated at 27.

against the lower surface of the base member 13. l

It will be vnoted that the lower ends of the end members 17 ofthe inner truss substantially vertically align with the upper ends of the end members 15 ofthe main truss and of the beams 18. Certain of the beams are arranged so that they immediately underlie the lower endsof theend members 17 so that the vertical'member 2OA associated therewith serves to tension the end members 15 and 17 and provide a diagonal for the parallelogram described by the base 13, upper member 14E and end members 15 and 17. Others of the cross beams are arranged vertically below the upper ends of the cross member 17 of the inner truss.

It will at once be obvious that a structure of this character will be very rigidandis comparatively free from the usualcantileve-r effect which causes bowing at the central portion of the bridge structure. rIhe weight at the center of the base member 13 is transi mitted to the upper ends 'of the end members 17 of the inner truss and is in turn transmitted by these end members to the base member at points adjacent the ends thereof where the cantilever effect meets with much greater resistance. Furthermore, the upper member 14 of the bridge structure which serves to provide the actual support, is securely braced from its lower member from pointsadjacent the ends thereof. The structure -thus provided is completely sheathed, as indicated at 21, and the cross beams 18 are likewise completely sheathed before they are placed in position. Upon these cross beams may be -laid the usual stringers 23 serving as a support for transversely extending flooring 25. Before thev flooring is applied, a sheet metal covering is applied to the upper surface of the ends thereof, as at 26, and this covering is continued upon the ends and below the flooring a sufficient distance to extend tothe upper surface of the beams 18. rllhis provides prothe structure thus. provided, between the m5 trusses 10, a layer ofl asphalt is laid, as in- It will be seen that little, if any, ofthe wooden structure of the bridge is subjected to the action of the element as in event the asphalt covering fails to make a proper joint with the trusses 10, the metal strips 26 will prevent damage to the ioor boards orstringers. It will also be obvious that a bridge oitl this character may be very readily and cheaply produced and installed and` Y will be durable and eficient in service.

It will also be obvious that the construction hereinbefore set forth is obviously cap! The combination in a wooden bridge having truss members, of cross beams connecting` said trusses and likewise having a metallic sheathing, stringers upon said cross beams', a flooring upon the stringere, a metallic covering` for the outer ends of the upper surface of the flooring, said metallic covering In testimony whereof I hereunto atix my signature.

yCASPER ZnviMniu/IAN, i

extending downwardly at the ends of the 

